The present invention relates to a method and a device for transmitting data on an aircraft.
It is known that most aircraft currently in service, in particular civil transport airplanes, are equipped with on-board electronic devices, in particular computers of the so-called xe2x80x9cavionic typexe2x80x9d. These electronic devices are used, in particular, for strategic functions of the flight of the aircraft, such as the flight controls. These devices must, consequently, exhibit a very high level of reliability, able to guarantee a lower rate of failure of the aircraft than that demanded by the certifying authorities. The communication networks and the links between such on-board devices (computers) of avionic type must meet the same reliability demands.
Certain modern transport airplanes, such as airplanes of the xe2x80x9cAirbus A340-600xe2x80x9d and xe2x80x9cAirbus A318xe2x80x9d type for example, also comprise so-called xe2x80x9copen worldxe2x80x9d on-board equipment, which is not specific to aeronautical applications. This xe2x80x9copen worldxe2x80x9d equipment consists of interface means (of xe2x80x9cman/machinexe2x80x9d type) available to an operator, in particular a pilot, of the airplane. By way of nonlimiting example, mention may be made of so called industrial computers, portable computers, printers, etc. This xe2x80x9copen worldxe2x80x9d equipment exhibits a lower level of reliability than that of the aforesaid devices of avionic type. It nevertheless exhibits the advantage of being much cheaper than these devices and its level of reliability is sufficient for the applications which are not directly related to maneuvers of the airplane, such as for example the consultation of maintenance documentation or the diagnostic help for aiding maintenance. When an airplane comprises interface means of open world type, it is sometimes beneficial to be able to use one or more of these interface means, to allow an operator to exchange information with devices of anionic type. This may be useful in particular within the framework of the airplane""s maintenance operations, so as to consult values of parameters available in devices of avionic type or to test certain components of the airplane (for example: electrical circuits, control surfaces, etc.), the maneuvering of which is controlled by such avionic type devices.
However, even if these maintenance operations exhibit a lesser criticality than that of the flight phases of the aircraft, the level of reliability of said interface means of open world type may not be sufficient in certain cases. Thus, by way of example, when a maintenance operation involves the maneuvering of a control surface, it is vital for the latter not to trigger inadvertently, since inadvertent triggering could be dangerous for personnel located in proximity to said control surface.
Consequently, one is generally strongly discouraged, in particular for reasons of reliability and hence of security, from implementing on an aircraft a transmission of sensitive data between a device of avionic type, such as described above, and an interface means of aforesaid type.
The object of the invention is to remedy these drawbacks. It relates to a method making it possible to achieve a particularly reliable transmission of data on an aircraft, between at least one device of avionic type and at least one interface means (of xe2x80x9copen worldxe2x80x9d type) which is available to an operator of said aircraft, said device and said interface means being capable of being connected together by way of a data transmission link.
To this end, according to the invention, said method is noteworthy in that in order to transmit at least one numerical value:
a) a textual message corresponding to said numerical value is formed;
b) said textual message is transmitted by way of said data transmission link;
c) said textual message transmitted is analyzed so as to detect any anomaly of said textual message transmitted; and
d) unless an anomaly is detected in step c), said textual message transmitted is processed.
Thus:
since by virtue of the invention the numerical value which one wishes to transmit is not transmitted directly, but instead a textual message specified hereinbelow and which corresponds to this numerical value is transmitted; and
since an error of transmission of such a textual message can be detected easily and reliably, as specified hereinbelow,
it is possible to detect most anomalies in the transmission of data between said device of avionic type and said interface means, thereby making it possible to achieve particularly reliable transmission of data, in both directions. The risk to security is therefore very small.
Furthermore, advantageously, in order to transmit at least one numerical value from said device of avionic type to said interface means:
said device automatically computes, in step a), the textual message corresponding to said numerical value; and/or
said interface means displays as it stands at step d) said textual message transmitted. In this case, preferably, the operator must perform a validation operation if he has received this textual message correctly, and/or
said interface means automatically analyzes, in step c), said textual message transmitted and, if it detects an anomaly in this step c), it displays an error message in step d).
Moreover, advantageously, in order to transmit at least one numerical value from said interface means to said device, in step a), an operator enters into said interface means:
the textual message directly; or
simply said numerical value. In this case:
said interface means displays the textual message corresponding to this numerical value entered, which it proposes to transmit; and
said operator must perform a validation operation in order for said interface means to transmit this textual message.
Moreover, advantageously, during the transmission of at least one numerical value from said interface means to said device, in step d):
if no anomaly has been detected in step c), said device automatically converts said textual message transmitted into a corresponding numerical value;
otherwise (detection of an anomaly), it returns a textual message to the interface means, intended to advise an operator of the anomaly.
Furthermore, advantageously, in a variant, in step a):
xcex1) the interface means displays a dispatch order from the operator, relating to the dispatch of a numerical value;
xcex2) the operator is invited to validate or to cancel this order; and
xcex3) if he validates the order, he is invited to enter a confirmation value and to confirm this entry so that the order is dispatched.
In this case, preferably, in the aforesaid step a), the interface means displays, as regards the dispatch order, simultaneously the numerical value and the corresponding textual message. Thus, if the operator enters the numerical value, the interface means also displays the corresponding textual message, and if the operator enters the textual message, the interface means also displays the numerical value. This makes it possible to guarantee that validation has indeed been effected voluntarily by the operator.
Moreover, in a particular embodiment, in order to transmit at least one numerical value from said interface means to said device:
an operator inputs the numerical value into the interface means and said interface means computes the corresponding textual message;
said interface means transmits this textual message to the device;
said device analyzes said textual message transmitted; and
if said device does not detect any anomaly, it sends a validation message to said interface means which displays it.
Furthermore, in another particular embodiment, in order to transmit at least one numerical value from said interface means to said device:
an operator inputs the numerical value into the interface means which transmits it to the device;
said device computes the textual message corresponding to the numerical value received;
said device transmits this textual message to the interface means which displays it; and
if the textual message displayed corresponds to the numerical value input initially by the operator, the latter performs a validation operation intended to inform said device that the numerical value received is correct.
According to the invention, in order to transmit said textual message in step b), successively:
b1) said textual message is coded as a corresponding digital message;
b2) said digital message is transmitted by way of said data transmission link of digital type; and
b3) the digital message thus transmitted is decoded to form said textual message transmitted.
Thus, by virtue of the invention, the standard digital-type link for data transmission is used to transmit the textual message (which is coded for this purpose digitally).
Furthermore, in order to form the textual message corresponding to said numerical value:
in a first embodiment, each digit of said numerical value is transformed individually into a textual equivalent, the textual message then corresponding to the string of said textual equivalents; and
in a second embodiment, said numerical value is transformed as a whole into a textual equivalent which then represents said textual message.
The present invention also relates to a data transmission system on board an aircraft, of the type comprising:
at least one device of avionic type;
at least one interface means available to an operator; and
at least one data transmission link capable of connecting together said device and said interface means.
According to the invention, said system is noteworthy in that said device and said interface means are formed so as to transmit any numerical value in the form of a corresponding textual message, and in that said device comprises at least one means for automatically carrying out, in both directions, the conversion between a numerical value and the corresponding textual message and at least one means for automatically detecting an anomaly of the textual message transmitted.
Thus, to obtain, on the basis of an existing (relatively unreliable) system, a data transmission system in accordance with the invention which is especially reliable, it is not necessary according to the invention to modify said existing system much, thereby making it possible in particular to reduce the cost.
Preferably, said interface means comprises a means of display and a means of entry of alphanumeric data.